﻿using FishNet.Connection;
using FishNet.Managing;
using FishNet.Managing.Logging;
using FishNet.Managing.Scened;
using FishNet.Transporting;
using FishNet.Utility;
using GameKit.Dependencies.Utilities;
using GameKit.Dependencies.Utilities.Types;
using System.IO;
using UnityEngine;
using UnityEngine.SceneManagement;
using UnityEngine.Serialization;
using UnitySceneManager = UnityEngine.SceneManagement.SceneManager;

namespace FishNet.Component.Scenes
{
    /// <summary>
    /// Add to a NetworkManager object to change between Online and Offline scene based on connection states of the server or client.
    /// </summary>
    [AddComponentMenu("FishNet/Component/DefaultScene")]
    public class DefaultScene : MonoBehaviour
    {
        #region Serialized.
        [Tooltip("True to load the online scene as global, false to load it as connection.")]
        [SerializeField]
        private bool _enableGlobalScenes = true;
        /// <summary>
        /// True to replace all scenes with the offline scene immediately.
        /// </summary>
        [Tooltip("True to replace all scenes with the offline scene immediately.")]
        [SerializeField]
        private bool _startInOffline;
        /// <summary>
        /// </summary>
        [Tooltip("Scene to load when disconnected. Server and client will load this scene.")]
        [SerializeField]
        [Scene]
        private string _offlineScene;

        /// <summary>
        /// Sets which offline scene to use.
        /// </summary>
        /// <param name = "sceneName">Scene name to use as the offline scene.</param>
        public void SetOfflineScene(string sceneName) => _offlineScene = sceneName;

        /// <summary>
        /// Scene to load when disconnected. Server and client will load this scene.
        /// </summary>
        /// <returns></returns>
        public string GetOfflineScene() => _offlineScene;

        /// <summary>
        /// </summary>
        [Tooltip("Scene to load when connected. Server and client will load this scene.")]
        [SerializeField]
        [Scene]
        private string _onlineScene;

        /// <summary>
        /// Sets which online scene to use.
        /// </summary>
        /// <param name = "sceneName">Scene name to use as the online scene.</param>
        public void SetOnlineScene(string sceneName) => _onlineScene = sceneName;

        /// <summary>
        /// Scene to load when connected. Server and client will load this scene.
        /// </summary>
        /// <returns></returns>
        public string GetOnlineScene() => _onlineScene;

        /// <summary>
        /// Which scenes to replace when loading into OnlineScene.
        /// </summary>
        [Tooltip("Which scenes to replace when loading into OnlineScene.")]
        [SerializeField]
        private ReplaceOption _replaceScenes = ReplaceOption.All;
        #endregion

        #region Private.
        /// <summary>
        /// NetworkManager for this component.
        /// </summary>
        private NetworkManager _networkManager;
        #endregion

        private void OnEnable()
        {
            Initialize();
        }

        private void OnDestroy()
        {
            Deinitialize();
        }

        /// <summary>
        /// Initializes this script for use.
        /// </summary>
        private void Initialize()
        {
            _networkManager = GetComponentInParent<NetworkManager>();
            if (_networkManager == null)
            {
                _networkManager.LogError($"NetworkManager not found on {gameObject.name} or any parent objects. DefaultScene will not work.");
                return;
            }
            // A NetworkManager won't be initialized if it's being destroyed.
            if (!_networkManager.Initialized)
                return;
            if (_onlineScene == string.Empty || _offlineScene == string.Empty)
            {
                _networkManager.LogWarning("Online or Offline scene is not specified. Default scenes will not load.");
                return;
            }

            _networkManager.ClientManager.OnClientConnectionState += ClientManager_OnClientConnectionState;
            _networkManager.ServerManager.OnServerConnectionState += ServerManager_OnServerConnectionState;
            _networkManager.SceneManager.OnLoadEnd += SceneManager_OnLoadEnd;
            _networkManager.ServerManager.OnAuthenticationResult += ServerManager_OnAuthenticationResult;
            if (_startInOffline)
                LoadOfflineScene();
        }

        private void Deinitialize()
        {
            if (!ApplicationState.IsQuitting() && _networkManager != null && _networkManager.Initialized)
            {
                _networkManager.ClientManager.OnClientConnectionState -= ClientManager_OnClientConnectionState;
                _networkManager.ServerManager.OnServerConnectionState -= ServerManager_OnServerConnectionState;
                _networkManager.SceneManager.OnLoadEnd -= SceneManager_OnLoadEnd;
                _networkManager.ServerManager.OnAuthenticationResult -= ServerManager_OnAuthenticationResult;
            }
        }

        /// <summary>
        /// Called when a scene load ends.
        /// </summary>
        private void SceneManager_OnLoadEnd(SceneLoadEndEventArgs obj)
        {
            bool onlineLoaded = false;
            foreach (Scene s in obj.LoadedScenes)
            {
                if (s.name == GetSceneName(_onlineScene))
                {
                    onlineLoaded = true;
                    break;
                }
            }

            // If online scene was loaded then unload offline.
            if (onlineLoaded)
                UnloadOfflineScene();
        }

        /// <summary>
        /// Called after the local server connection state changes.
        /// </summary>
        private void ServerManager_OnServerConnectionState(ServerConnectionStateArgs obj)
        {
            /* When server starts load online scene as global.
             * Since this is a global scene clients will automatically
             * join it when connecting. */
            if (obj.ConnectionState == LocalConnectionState.Started)
            {
                /* If not exactly one server is started then
                 * that means either none are started, which isnt true because
                 * we just got a started callback, or two+ are started.
                 * When a server has already started there's no reason to load
                 * scenes again. */
                if (!_networkManager.ServerManager.IsOnlyOneServerStarted())
                    return;

                // If here can load scene.
                SceneLoadData sld = new(GetSceneName(_onlineScene));
                sld.ReplaceScenes = _replaceScenes;
                if (_enableGlobalScenes)
                    _networkManager.SceneManager.LoadGlobalScenes(sld);
                else
                    _networkManager.SceneManager.LoadConnectionScenes(sld);
            }
            // When server stops load offline scene.
            else if (obj.ConnectionState == LocalConnectionState.Stopped && !_networkManager.ServerManager.IsAnyServerStarted())
            {
                LoadOfflineScene();
            }
        }

        /// <summary>
        /// Called after the local client connection state changes.
        /// </summary>
        private void ClientManager_OnClientConnectionState(ClientConnectionStateArgs obj)
        {
            if (obj.ConnectionState == LocalConnectionState.Stopped)
            {
                // Only load offline scene if not also server.
                if (!_networkManager.IsServerStarted)
                    LoadOfflineScene();
            }
        }

        /// <summary>
        /// Called when a client completes authentication.
        /// </summary>
        private void ServerManager_OnAuthenticationResult(NetworkConnection arg1, bool authenticated)
        {
            /* This is only for loading connection scenes.
             * If using global there is no need to continue. */
            if (_enableGlobalScenes)
                return;
            if (!authenticated)
                return;

            SceneLoadData sld = new(GetSceneName(_onlineScene));
            _networkManager.SceneManager.LoadConnectionScenes(arg1, sld);
        }

        /// <summary>
        /// Loads offlineScene as single.
        /// </summary>
        private void LoadOfflineScene()
        {
            // Already in offline scene.
            if (UnitySceneManager.GetActiveScene().name == GetSceneName(_offlineScene))
                return;
            // Only use scene manager if networking scenes. I may add something in later to do both local and networked.
            UnitySceneManager.LoadScene(_offlineScene);
        }

        /// <summary>
        /// Unloads the offline scene.
        /// </summary>
        private void UnloadOfflineScene()
        {
            Scene s = UnitySceneManager.GetSceneByName(GetSceneName(_offlineScene));
            if (string.IsNullOrEmpty(s.name))
                return;

            UnitySceneManager.UnloadSceneAsync(s);
        }

        /// <summary>
        /// Returns a scene name from fullPath.
        /// </summary>
        /// <param name = "fullPath"></param>
        /// <returns></returns>
        private string GetSceneName(string fullPath)
        {
            return Path.GetFileNameWithoutExtension(fullPath);
        }
    }
}